Mixing Pascal and Snake casing

I'm working on a test naming convention document with my team (for tests mostly in NUnit/C#), and while we are primarily using Pascal Casing in the test names there is a strong desire from the team to use underscores as natural breaks in test names, for example;

[TestClassName]_WhatTheTestDoes

or

TestClassNameWhatTheTestDoes_ButTheDescriptionIsReallyLongForGoodReason_AndWeAreUsingTheUnderscoresForReadability

Note that in the latter example this is NOT a case where the test is executing too much functionality - the description honestly just has to be longish to describe our functionality accurately.

Is there a term for either of these mixed cases?